//

//

//  Created by Bogdan Timofte on 09/03/2020.

//  Copyright © 2020 Bogdan Timofte. All rights reserved.

//

import SwiftUI

    var availableSize: CGSize? = nil

    var body: some View {

                    .font(.headline)

                Spacer()

                statusBadge

            }

                MeterInfoRowView(label: "Name", value: meter.name.isEmpty ? "Meter" : meter.name)

                MeterInfoRowView(label: "Model", value: meter.deviceModelSummary)

                MeterInfoRowView(label: "Advertised Model", value: meter.modelString)

                MeterInfoRowView(label: "MAC", value: meter.btSerial.macAddress.description)

                MeterInfoRowView(label: "Last Seen", value: meterHistoryText(for: meter.lastSeen))

                MeterInfoRowView(label: "Last Connected", value: meterHistoryText(for: meter.lastConnectedAt))

            }

                destination: ChargerStandbyPowerWizardView(

                    preferredMeterMACAddress: meter.btSerial.macAddress.description

                )

            ) {

                standbyWizardCard

            }

            .buttonStyle(.plain)

                    liveMetricCard(

                        title: "Voltage",

                        symbol: "bolt.fill",

                        color: .green,

                        value: "\(meter.voltage.format(decimalDigits: 3)) V",

                        range: metricRange(

                            min: meter.measurements.voltage.context.minValue,

                            max: meter.measurements.voltage.context.maxValue,

                            unit: "V"

                        )

                    liveMetricCard(

                        title: "Current",

                        symbol: "waveform.path.ecg",

                        color: .blue,

                        value: "\(meter.current.format(decimalDigits: 3)) A",

                        range: metricRange(

                            min: meter.measurements.current.context.minValue,

                            max: meter.measurements.current.context.maxValue,

                            unit: "A"

                        )

                    liveMetricCard(

                        title: "Power",

                        symbol: "flame.fill",

                        color: .pink,

                        value: "\(meter.power.format(decimalDigits: 3)) W",

                        range: metricRange(

                            min: meter.measurements.power.context.minValue,

                            max: meter.measurements.power.context.maxValue,

                            unit: "W"

                        action: {

                            powerAverageSheetVisibility = true

                        }

                    liveMetricCard(

                        color: .teal,

                        value: "\(liveBufferedEnergyValue.format(decimalDigits: 3)) Wh",

                        action: {

                            energyProjectionSheetVisibility = true

                        }

                }

                    liveMetricCard(

                        title: "Temperature",

                        symbol: "thermometer.medium",

                        color: .orange,

                        value: meter.primaryTemperatureDescription,

                            min: meter.measurements.temperature.context.minValue,

                            max: meter.measurements.temperature.context.maxValue

                        )

                }

                    liveMetricCard(

                        title: "Load",

                        customSymbol: AnyView(LoadResistanceIconView(color: .yellow)),

                        color: .yellow,

                        value: "\(meter.loadResistance.format(decimalDigits: 1)) \u{2126}",

                        detailText: "Measured resistance"

                    )

                }

                    title: "RSSI",

                    symbol: "dot.radiowaves.left.and.right",

                    color: .mint,

                        min: meter.measurements.rssi.context.minValue,

                        max: meter.measurements.rssi.context.maxValue,

                        unit: "dBm",

                        decimalDigits: 0

                    action: {

                        rssiHistorySheetVisibility = true

                    }

                        title: "Detected Charger",

                        symbol: "powerplug.fill",

                        color: .indigo,

                        value: meter.chargerTypeDescription,

                        detailText: "Source handshake",

                        valueFont: .system(compactLayout ? .subheadline : .headline, design: .rounded).weight(.bold),

                        valueLineLimit: 2,

                        valueMonospacedDigits: false,

                        valueMinimumScaleFactor: 0.72

                    )

                }

        }

            PowerAverageSheetView(visibility: $powerAverageSheetVisibility)

                .environmentObject(meter.measurements)

        }

            EnergyProjectionSheetView(visibility: $energyProjectionSheetVisibility)

                .environmentObject(meter.measurements)

                .environmentObject(meter)

        }

            RSSIHistorySheetView(visibility: $rssiHistorySheetVisibility)

                .environmentObject(meter.measurements)

        }

        meter.operationalState == .dataIsAvailable

    }

    private var shouldShowVoltageCard: Bool {

        hasLiveMetrics && meter.measurements.voltage.context.isValid && meter.voltage.isFinite

    }

    private var shouldShowCurrentCard: Bool {

        hasLiveMetrics && meter.measurements.current.context.isValid && meter.current.isFinite

    }

    private var shouldShowPowerCard: Bool {

        hasLiveMetrics && meter.measurements.power.context.isValid && meter.power.isFinite

    }

        hasLiveMetrics && meter.measurements.energy.context.isValid && liveBufferedEnergyValue.isFinite

    }

        hasLiveMetrics && meter.displayedTemperatureValue.isFinite

    }

        meter.measurements.energy.samplePoints.last?.value ?? 0

    }

        hasLiveMetrics && meter.loadResistance.isFinite && meter.loadResistance > 0

    }

        if compactLayout {

        return [GridItem(.flexible()), GridItem(.flexible())]

    private var statusBadge: some View {

        Text(meter.operationalState == .dataIsAvailable ? "Live" : "Waiting")

            .font(.caption.weight(.semibold))

            .padding(.horizontal, 10)

            .padding(.vertical, 6)

            .foregroundColor(meter.operationalState == .dataIsAvailable ? .green : .secondary)

            .meterCard(

                tint: meter.operationalState == .dataIsAvailable ? .green : .secondary,

                fillOpacity: 0.12,

                strokeOpacity: 0.16,

                cornerRadius: 999

            )

    }

        MeterInfoCardView(title: "Standby Power", tint: .orange) {

            Label("New Measurement", systemImage: "plus.circle.fill")

                .font(.subheadline.weight(.semibold))

                .foregroundColor(.orange)

            if let session = appData.chargerStandbyMeasurementSession(for: meter.btSerial.macAddress.description) {

                Text(

                    "Active on \(appData.chargedDeviceSummary(id: session.chargerID)?.name ?? "selected charger") • \(session.readinessDescription)"

                )

                .font(.caption)

                .foregroundColor(.secondary)

            } else if let charger = appData.currentChargerSummary(for: meter.btSerial.macAddress.description) {

                Text(

                    charger.latestStandbyPowerMeasurement.map {

                        "\(charger.name) • latest \($0.averagePowerWatts.format(decimalDigits: 3)) W"

                    } ?? "\(charger.name) • no saved standby baseline"

                )

                .font(.caption)

                .foregroundColor(.secondary)

            } else {

                Text("Open the wizard and choose the charger there.")

                    .font(.caption)

                    .foregroundColor(.secondary)

                    .frame(maxWidth: .infinity, alignment: .leading)

            }

        }

    }

        compactLayout && (availableSize?.height ?? 0) >= 380

    }

    private var shouldShowMetricRange: Bool {

        !compactLayout || showsCompactMetricRange

    }

        title: String,

        customSymbol: AnyView? = nil,

        value: String,

        valueFont: Font? = nil,

        valueLineLimit: Int = 1,

        valueMonospacedDigits: Bool = true,

        action: (() -> Void)? = nil

                    if let customSymbol {

                        customSymbol

                    } else if let symbol {

                        Image(systemName: symbol)

                            .font(.system(size: compactLayout ? 14 : 15, weight: .semibold))

                            .foregroundColor(color)

                    }

                }

                    .font((compactLayout ? Font.caption : .subheadline).weight(.semibold))

                    .foregroundColor(.secondary)

                    .lineLimit(1)

                Spacer(minLength: 0)

            }

                if valueMonospacedDigits {

                    Text(value)

                        .monospacedDigit()

                } else {

                    Text(value)

                }

            }

            .font(valueFont ?? .system(compactLayout ? .headline : .title3, design: .rounded).weight(.bold))

            .lineLimit(valueLineLimit)

            .minimumScaleFactor(valueMinimumScaleFactor)

                if let range {

                    metricRangeTable(range)

                } else if let detailText, !detailText.isEmpty {

                    Text(detailText)

                        .font(.caption)

                        .foregroundColor(.secondary)

                        .lineLimit(2)

                }

        }

            maxWidth: .infinity,

        )

        .padding(compactLayout ? 12 : 16)

        if let action {

            return AnyView(

                Button(action: action) {

                    cardContent

                }

                .buttonStyle(.plain)

            )

        }

        return AnyView(cardContent)

            HStack(spacing: 12) {

                Text(range.minLabel)

                Spacer(minLength: 0)

                Text(range.maxLabel)

            }

            .font(.caption2.weight(.semibold))

            .foregroundColor(.secondary)

            HStack(spacing: 12) {

                Text(range.minValue)

                    .monospacedDigit()

                Spacer(minLength: 0)

                Text(range.maxValue)

                    .monospacedDigit()

            }

            .font(.caption.weight(.medium))

            .foregroundColor(.primary)

        }

    }

            maxLabel: "Max",

            maxValue: "\(max.format(decimalDigits: decimalDigits)) \(unit)"

    }

        guard min.isFinite, max.isFinite else { return nil }

        let unitSuffix = temperatureUnitSuffix()

            maxLabel: "Max",

            maxValue: "\(max.format(decimalDigits: 0))\(unitSuffix)"

    private func meterHistoryText(for date: Date?) -> String {

        guard let date else {

            return "Never"

        }

        return date.format(as: "yyyy-MM-dd HH:mm")

    }

    private func temperatureUnitSuffix() -> String {

        if meter.supportsManualTemperatureUnitSelection {

            return "°"

        }

        let locale = Locale.autoupdatingCurrent

        if #available(iOS 16.0, *) {

            switch locale.measurementSystem {

            case .us:

                return "°F"

            default:

                return "°C"

            }

        }

        let regionCode = locale.regionCode ?? ""

        let fahrenheitRegions: Set<String> = ["US", "BS", "BZ", "KY", "PW", "LR", "FM", "MH"]

        return fahrenheitRegions.contains(regionCode) ? "°F" : "°C"

    }

}

private struct PowerAverageSheetView: View {

    @EnvironmentObject private var measurements: Measurements

    @Binding var visibility: Bool

    @State private var selectedSampleCount: Int = 20

    var body: some View {

        let bufferedSamples = measurements.powerSampleCount()

        NavigationView {

            ScrollView {

                VStack(alignment: .leading, spacing: 14) {

                    VStack(alignment: .leading, spacing: 8) {

                            Text("Power Average")

                                .font(.system(.title3, design: .rounded).weight(.bold))

                            ContextInfoButton(

                                title: "Power Average",

                                message: "Inspect the recent power buffer, choose how many values to include, and compute the average power over that window."

                            )

                        }

                    .padding(18)

                    .meterCard(tint: .pink, fillOpacity: 0.18, strokeOpacity: 0.24)

                    MeterInfoCardView(title: "Average Calculator", tint: .pink) {

                        if bufferedSamples == 0 {

                            Text("No power samples are available yet.")

                                .font(.footnote)

                                .foregroundColor(.secondary)

                        } else {

                            VStack(alignment: .leading, spacing: 14) {

                                VStack(alignment: .leading, spacing: 8) {

                                    Text("Values used")

                                        .font(.subheadline.weight(.semibold))

                                    Picker("Values used", selection: selectedSampleCountBinding(bufferedSamples: bufferedSamples)) {

                                        ForEach(availableSampleOptions(bufferedSamples: bufferedSamples), id: \.self) { option in

                                            Text(sampleOptionTitle(option, bufferedSamples: bufferedSamples)).tag(option)

                                        }

                                    }

                                    .pickerStyle(.menu)

                                }

                                VStack(alignment: .leading, spacing: 6) {

                                    Text(averagePowerLabel(bufferedSamples: bufferedSamples))

                                        .font(.system(.title2, design: .rounded).weight(.bold))

                                        .monospacedDigit()

                                    Text("Buffered samples: \(bufferedSamples)")

                                        .font(.caption)

                                        .foregroundColor(.secondary)

                                }

                            }

                        }

                    }

                        title: "Buffer Actions",

                        infoMessage: "Reset clears the captured live measurement buffer for power, energy, voltage, current, temperature, and RSSI.",

                        tint: .secondary

                    ) {

                            measurements.resetSeries()

                            selectedSampleCount = defaultSampleCount(bufferedSamples: measurements.powerSampleCount(flushPendingValues: false))

                        }

                        .foregroundColor(.red)

                    }

                }

                .padding()

            }

            .background(

                LinearGradient(

                    colors: [.pink.opacity(0.14), Color.clear],

                    startPoint: .topLeading,

                    endPoint: .bottomTrailing

                )

                .ignoresSafeArea()

            )

            .navigationBarItems(

                leading: Button("Done") { visibility.toggle() }

            )

            .navigationBarTitle("Power", displayMode: .inline)

        }

        .navigationViewStyle(StackNavigationViewStyle())

        .onAppear {

            selectedSampleCount = defaultSampleCount(bufferedSamples: bufferedSamples)

        }

        .onChange(of: bufferedSamples) { newValue in

            selectedSampleCount = min(max(1, selectedSampleCount), max(1, newValue))

        }

    }

    private func availableSampleOptions(bufferedSamples: Int) -> [Int] {

        guard bufferedSamples > 0 else { return [] }

        let filtered = measurements.averagePowerSampleOptions.filter { $0 < bufferedSamples }

        return (filtered + [bufferedSamples]).sorted()

    }

    private func defaultSampleCount(bufferedSamples: Int) -> Int {

        guard bufferedSamples > 0 else { return 20 }

        return min(20, bufferedSamples)

    }

    private func selectedSampleCountBinding(bufferedSamples: Int) -> Binding<Int> {

        Binding(

            get: {

                let availableOptions = availableSampleOptions(bufferedSamples: bufferedSamples)

                guard !availableOptions.isEmpty else { return defaultSampleCount(bufferedSamples: bufferedSamples) }

                if availableOptions.contains(selectedSampleCount) {

                    return selectedSampleCount

                }

                return min(availableOptions.last ?? bufferedSamples, defaultSampleCount(bufferedSamples: bufferedSamples))

            },

            set: { newValue in

                selectedSampleCount = newValue

            }

        )

    }

    private func sampleOptionTitle(_ option: Int, bufferedSamples: Int) -> String {

        if option == bufferedSamples {

            return "All (\(option))"

        }

        return "\(option) values"

    }

    private func averagePowerLabel(bufferedSamples: Int) -> String {

        guard let average = measurements.averagePower(forRecentSampleCount: selectedSampleCount, flushPendingValues: false) else {

            return "No data"

        }

        let effectiveSampleCount = min(selectedSampleCount, bufferedSamples)

        return "\(average.format(decimalDigits: 3)) W avg (\(effectiveSampleCount))"

    }

}

private struct RSSIHistorySheetView: View {

    @EnvironmentObject private var measurements: Measurements

    @Binding var visibility: Bool

    private let xLabels: Int = 4

    private let yLabels: Int = 4

    var body: some View {

        let points = measurements.rssi.points

        let samplePoints = measurements.rssi.samplePoints

        let chartContext = buildChartContext(for: samplePoints)

        NavigationView {

            ScrollView {

                VStack(alignment: .leading, spacing: 14) {

                    VStack(alignment: .leading, spacing: 8) {

                            Text("RSSI History")

                                .font(.system(.title3, design: .rounded).weight(.bold))

                            ContextInfoButton(

                                title: "RSSI History",

                                message: "Signal strength captured over time while the meter stays connected."

                            )

                        }

                    .padding(18)

                    .meterCard(tint: .mint, fillOpacity: 0.18, strokeOpacity: 0.24)

                    if samplePoints.isEmpty {

                        Text("No RSSI samples have been captured yet.")

                            .font(.footnote)

                            .foregroundColor(.secondary)

                            .padding(18)

                            .meterCard(tint: .secondary, fillOpacity: 0.14, strokeOpacity: 0.20)

                    } else {

                        MeterInfoCardView(title: "Signal Chart", tint: .mint) {

                            VStack(alignment: .leading, spacing: 12) {

                                HStack(spacing: 12) {

                                    signalSummaryChip(title: "Current", value: "\(Int(samplePoints.last?.value ?? 0)) dBm")

                                    signalSummaryChip(title: "Min", value: "\(Int(samplePoints.map(\.value).min() ?? 0)) dBm")

                                    signalSummaryChip(title: "Max", value: "\(Int(samplePoints.map(\.value).max() ?? 0)) dBm")

                                }

                                HStack(spacing: 8) {

                                    rssiYAxisView(context: chartContext)

                                        .frame(width: 52, height: 220)

                                    ZStack {

                                        RoundedRectangle(cornerRadius: 18, style: .continuous)

                                            .fill(Color.primary.opacity(0.05))

                                        RoundedRectangle(cornerRadius: 18, style: .continuous)

                                            .stroke(Color.secondary.opacity(0.16), lineWidth: 1)

                                        rssiHorizontalGuides(context: chartContext)

                                        rssiVerticalGuides(context: chartContext)

                                        Chart(points: points, context: chartContext, strokeColor: .mint)

                                            .opacity(0.82)

                                    }

                                    .frame(maxWidth: .infinity)

                                    .frame(height: 220)

                                }

                                rssiXAxisLabelsView(context: chartContext)

                                    .frame(height: 28)

                            }

                        }

                    }

                }

                .padding()

            }

            .background(

                LinearGradient(

                    colors: [.mint.opacity(0.14), Color.clear],

                    startPoint: .topLeading,

                    endPoint: .bottomTrailing

                )

                .ignoresSafeArea()

            )

            .navigationBarItems(

                leading: Button("Done") { visibility.toggle() }

            )

            .navigationBarTitle("RSSI", displayMode: .inline)

        }

        .navigationViewStyle(StackNavigationViewStyle())

    }

    private func buildChartContext(for samplePoints: [Measurements.Measurement.Point]) -> ChartContext {

        let context = ChartContext()

        let upperBound = max(samplePoints.last?.timestamp ?? Date(), Date())

        let lowerBound = samplePoints.first?.timestamp ?? upperBound.addingTimeInterval(-60)

        let minimumValue = samplePoints.map(\.value).min() ?? -100

        let maximumValue = samplePoints.map(\.value).max() ?? -40

        let padding = max((maximumValue - minimumValue) * 0.12, 4)

        context.setBounds(

            xMin: CGFloat(lowerBound.timeIntervalSince1970),

            xMax: CGFloat(max(upperBound.timeIntervalSince1970, lowerBound.timeIntervalSince1970 + 1)),

            yMin: CGFloat(minimumValue - padding),

            yMax: CGFloat(maximumValue + padding)

        )

        return context

    }

    private func signalSummaryChip(title: String, value: String) -> some View {

        VStack(alignment: .leading, spacing: 4) {

            Text(title)

                .font(.caption.weight(.semibold))

                .foregroundColor(.secondary)

            Text(value)

                .font(.subheadline.weight(.bold))

                .monospacedDigit()

        }

        .padding(.horizontal, 12)

        .padding(.vertical, 10)

        .meterCard(tint: .mint, fillOpacity: 0.10, strokeOpacity: 0.14, cornerRadius: 14)

    }

    private func rssiXAxisLabelsView(context: ChartContext) -> some View {

        let labels = (1...xLabels).map {

            Date(timeIntervalSince1970: context.xAxisLabel(for: $0, of: xLabels)).format(as: "HH:mm:ss")

        }

        return HStack {

            ForEach(Array(labels.enumerated()), id: \.offset) { item in

                Text(item.element)

                    .font(.caption2.weight(.semibold))

                    .monospacedDigit()

                    .frame(maxWidth: .infinity)

            }

        }

        .foregroundColor(.secondary)

    }

    private func rssiYAxisView(context: ChartContext) -> some View {

        VStack(spacing: 0) {

            ForEach((1...yLabels).reversed(), id: \.self) { labelIndex in

                Spacer(minLength: 0)

                Text("\(context.yAxisLabel(for: labelIndex, of: yLabels).format(decimalDigits: 0))")

                    .font(.caption2.weight(.semibold))

                    .monospacedDigit()

                    .foregroundColor(.primary)

                Spacer(minLength: 0)

            }

        }

        .padding(.vertical, 12)

        .background(

            RoundedRectangle(cornerRadius: 16, style: .continuous)

                .fill(Color.mint.opacity(0.12))

        )

        .overlay(

            RoundedRectangle(cornerRadius: 16, style: .continuous)

                .stroke(Color.mint.opacity(0.20), lineWidth: 1)

        )

    }

    private func rssiHorizontalGuides(context: ChartContext) -> some View {

        GeometryReader { geometry in

            Path { path in

                for labelIndex in 1...yLabels {

                    let value = context.yAxisLabel(for: labelIndex, of: yLabels)

                    let anchorPoint = CGPoint(x: context.origin.x, y: CGFloat(value))

                    let y = context.placeInRect(point: anchorPoint).y * geometry.size.height

                    path.addLine(from: CGPoint(x: 0, y: y), to: CGPoint(x: geometry.size.width, y: y))

                }

            }

            .stroke(Color.secondary.opacity(0.30), lineWidth: 0.8)

        }

    }

    private func rssiVerticalGuides(context: ChartContext) -> some View {

        GeometryReader { geometry in

            Path { path in

                for labelIndex in 2..<xLabels {

                    let value = context.xAxisLabel(for: labelIndex, of: xLabels)

                    let anchorPoint = CGPoint(x: CGFloat(value), y: context.origin.y)

                    let x = context.placeInRect(point: anchorPoint).x * geometry.size.width

                    path.move(to: CGPoint(x: x, y: 0))

                    path.addLine(to: CGPoint(x: x, y: geometry.size.height))

                }

            }

            .stroke(Color.secondary.opacity(0.26), style: StrokeStyle(lineWidth: 0.8, dash: [4, 4]))

        }

    }

private struct EnergyProjectionSheetView: View {

    @EnvironmentObject private var measurements: Measurements

    @EnvironmentObject private var meter: Meter

    @Binding var visibility: Bool

    @State private var selectedProjectionMethodID: String = ""

    var body: some View {

        let snapshot = measurements.energyProjectionSnapshot()

        let projectionVariants = measurements.energyProjectionVariants()

        let projectionVariantIDs = projectionVariants.map(\.id)

        let selectedProjectionVariant = resolvedProjectionVariant(from: projectionVariants)

        NavigationView {

            ScrollView {

                VStack(alignment: .leading, spacing: 14) {

                    VStack(alignment: .leading, spacing: 8) {

                            Text("Energy Projections")

                                .font(.system(.title3, design: .rounded).weight(.bold))

                            ContextInfoButton(

                                title: "Energy Projections",

                                message: "Projected consumption is estimated from multiple real windows in the live buffer. A method is shown only when that full interval exists in the recent continuous data."

                            )

                        }

                    .padding(18)

                    .meterCard(tint: .teal, fillOpacity: 0.18, strokeOpacity: 0.24)

                    MeterInfoCardView(title: "Current Session", tint: meter.color) {

                        if let snapshot {

                            MeterInfoRowView(

                                label: "Accumulated Energy",

                                value: "\(snapshot.accumulatedEnergy.format(decimalDigits: 3)) Wh"

                            )

                            MeterInfoRowView(

                                label: "Observed Interval",

                                value: observedIntervalText(snapshot.observedDuration)

                            )

                            MeterInfoRowView(

                                label: "Buffered Samples",

                                value: "\(snapshot.sampleCount)"

                            )

                            MeterInfoRowView(

                                label: "Average Power",

                                value: averagePowerText(snapshot.averagePower)

                            )

                        } else {

                            Text("Not enough live energy data yet. Keep the meter connected for a little longer, then reopen this view.")

                                .font(.footnote)

                                .foregroundColor(.secondary)

                        }

                    }

                        title: "Projection Method",

                        infoMessage: "Projection methods appear after the live buffer contains at least one continuous interval with enough data to estimate a rate.",

                        tint: .teal

                    ) {

                                .foregroundColor(.secondary)

                        } else {

                            VStack(alignment: .leading, spacing: 14) {

                                Picker("Projection Method", selection: selectedProjectionMethodBinding(for: projectionVariants)) {

                                    ForEach(projectionVariants) { variant in

                                        Text(variant.title).tag(variant.id)

                                    }

                                }

                                .pickerStyle(.menu)

                                if let selectedProjectionVariant {

                                    projectionVariantView(selectedProjectionVariant)

                                }

                            }

                        }

                    }

                }

                .padding()

                .padding(.top, 8)

            }

            .background(

                LinearGradient(

                    colors: [.teal.opacity(0.14), Color.clear],

                    startPoint: .topLeading,

                    endPoint: .bottomTrailing

                )

                .ignoresSafeArea()

            )

            .navigationTitle("Energy")

            .navigationBarTitleDisplayMode(.inline)

            .toolbar {

                ToolbarItem(placement: .cancellationAction) {

                    Button("Done") { visibility.toggle() }

                }

            }

        }

        .navigationViewStyle(StackNavigationViewStyle())

        .onAppear {

            updateSelectedProjectionMethod(with: projectionVariants)

        }

        .onChange(of: projectionVariantIDs) { _ in

            updateSelectedProjectionMethod(with: projectionVariants)

        }

    }

    private func projectionRow(title: String, value: String) -> some View {

        MeterInfoRowView(label: title, value: value)

    }

    private func projectionVariantView(_ variant: Measurements.EnergyProjectionVariant) -> some View {

        VStack(alignment: .leading, spacing: 8) {

            Text(variant.title)

                .font(.subheadline.weight(.semibold))

            projectionRow(title: "Observed Interval", value: observedIntervalText(variant.observedDuration))

            projectionRow(title: "Window Energy", value: energyText(variant.accumulatedEnergy))

            projectionRow(title: "Average Power", value: averagePowerText(variant.averagePower))

            projectionRow(title: "Monthly", value: projectedEnergyText(variant.projectedMonthlyEnergy))

            projectionRow(title: "Yearly", value: projectedEnergyText(variant.projectedYearlyEnergy))

        }

        .padding(.bottom, 2)

    }

    private func resolvedProjectionVariant(from variants: [Measurements.EnergyProjectionVariant]) -> Measurements.EnergyProjectionVariant? {

        if let selectedVariant = variants.first(where: { $0.id == selectedProjectionMethodID }) {

            return selectedVariant

        }

        return variants.last

    }

    private func selectedProjectionMethodBinding(

        for variants: [Measurements.EnergyProjectionVariant]

    ) -> Binding<String> {

        Binding(

            get: {

                resolvedProjectionVariant(from: variants)?.id ?? ""

            },

            set: { newValue in

                selectedProjectionMethodID = newValue

            }

        )

    }

    private func updateSelectedProjectionMethod(with variants: [Measurements.EnergyProjectionVariant]) {

        guard !variants.isEmpty else {

            selectedProjectionMethodID = ""

            return

        }

        if variants.contains(where: { $0.id == selectedProjectionMethodID }) {

            return

        }

        selectedProjectionMethodID = variants.last?.id ?? ""

    }

    private func observedIntervalText(_ duration: TimeInterval) -> String {

        guard duration > 0 else { return "Insufficient data" }

        let totalSeconds = Int(duration.rounded())

        let hours = totalSeconds / 3600

        let minutes = (totalSeconds % 3600) / 60

        let seconds = totalSeconds % 60

        if hours > 0 {

            return "\(hours)h \(minutes)m"

        }

        if minutes > 0 {

            return "\(minutes)m \(seconds)s"

        }

        return "\(seconds)s"

    }

    private func averagePowerText(_ averagePower: Double?) -> String {

        guard let averagePower, averagePower.isFinite else {

            return "Insufficient data"

        }

        return "\(averagePower.format(decimalDigits: 3)) W"

    }

    private func averagePowerText(_ averagePower: Double) -> String {

        averagePowerText(Optional(averagePower))

    }

    private func energyText(_ energy: Double) -> String {

        if energy >= 1000 {

            return "\((energy / 1000).format(decimalDigits: 3)) kWh"

        }

        return "\(energy.format(decimalDigits: 3)) Wh"

    }

    private func projectedEnergyText(_ energy: Double?) -> String {

        guard let energy, energy.isFinite else {

            return "Insufficient data"

        }

        if energy >= 1000 {

            return "\((energy / 1000).format(decimalDigits: 3)) kWh"

        }

        return "\(energy.format(decimalDigits: 1)) Wh"

    }

}